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AMPLIFIER REPAIRS NOTTINGHAM, DERBY, LEICESTER, LINCOLN

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I have over 40 years of experience in refurbishing and repairing all types of amplifiers to the highest standard. I'm based near Nottingham, with easy access from the M1, A46 and A1. Please don't hesitate to contact me if you have a requirement that is not specifically mentioned on the website.

Icon Audio Stereo 40 MkIIIm

A new customer Steve brought me is beautiful Icon Audio power amp for a small repair. He had decided to changeover to KT88s, which necessitated readjusting the bias. On this amp there are four individual miniature trimmers, one per valve. Unfortunately one had got damaged (it was rotating 360 degrees - broken shaft) and therefore the bias could not be adjusted. When I checked them all, non of them felt 'right', so we agreed to change all four. Credit to Icon Audio they sent replacements free of charge. All done and sounding pretty awesome, despite my little bookshelf test speakers !  

VOX AC30TB

Received an 11th hour call from the equipment tech of the Michael Ball / Alfie Boe concert at the Nottingham Arena, the backing guitarist's main AC30TB was playing up and could I look at it when they arrived in Nottingham in time for the gig. It turned out to be pretty straightforward and easily sorted, for starters two of the output valves were 'red-plating' and basically 'cooking' themselves (they do get a hard time with the amount of cathode bias applied in AC30s), plus a preamp valve had also died. A new matched quad of JJ EL84s, plus a bias check, new pre-amp valve and through check over and all was sweet.
It did look a bit road worn I have to say, but ended up sounding pretty awesome, and apparently the show went well, so I am glad I was able to contribute in some small way. 

Ampeg Portaflex B15 bass amp

Well, here's something you don't see every day, a mid '60s Ampeg Portaflex 15, this beauty was brought in by a new customer Andy, basically, the amp sits inverted inside the cab, and is swapped around to play, great concept. This one did need a bit of TLC, including new mains cabling, a cap job, new output valves, but when finished sounded awesome!  

Mastersound 300B Valve Hi-Fi amp

Carmine, a new customer, brought me his awesome Mastersound 300B Hi-Fi amp, which he suspected had a faulty valve as it was blowing the HT fuse. I did a quick schematic of the output stage, and then tested the valves on my '60s AVO CT160, it turned out to be exactly the case. Having fitted a new valve and also reset the bias, (despite being cathode biased they are individually adjustable), it sounded absolutely awesome.  

Fender SilverFace Twin Reverb

Richard, a new customer brought me his recently purchased Silverface Twin Reverb for a major overall, amongst things that needed doing were full electrolytic cap job, new output valves, new reverb tank and a thorough service. It left sounding super loud and super clean, and Richard was very happy, he had previously had one and unfortunately had to let it go, this time he is determined to hang on to this beauty. At the time I had a few nice Fenders in the workshop including a Blackface Vibroverb, with 15 inch JBL - quite a rare beast.  

Valve mono-block power amps and preamp

Carl brought me his pair of mono-block Hi-Fi amps and pre-amp, which were based on a Williamson design of the late 1940's. Carl free issued me with a set of new valves and also asked for a service. I did find a number of components out of tolerance and a mains filter cap had died (see photo). Having done all that and set the bias, the amp sounded pretty amazing even with my test speakers. Carl was very knowledgeable and knew exactly what he wanted, which does help a lot     

Fender Hotrod Deluxe

A very popular amp with gigging musicians, they are a real workhorse, very loud, not too heavy and very versatile, I see a lot them. This particular one, a lovely example, was blowing the mains fuse. A quick test of the output valves confirmed my suspicions that one had arced over internally (probably screen grid to cathode), thus blowing the fuse. However it had also taken out the screen grid resistor in the process. I cleaned up the board and fitted larger wattage replacements to both valves, and gave the amp a full service in the process.    

Fender Princeton Blackface

A good friend of mine Alex, who is a guitar tutor, session player and band player, brought me his latest acquisition, a lovey mid 60's Princeton reverb, which was a US amp and asked me to swap the mains transformer for a UK version. I have done quite a number of transformer swaps over the years, personally I use Hammond transformers from Canada, if they have a suitable replacement. I always recommend people do this with US amps, because it saves carrying a step down transformer around (even if mounted in the cab, it all adds weight) and it removes several points of failure, e.g. cables, plugs and the transformer itself.   

Vox AC15 Copper top

What a beauty,  Tony brought me this awesome early '60s AC15, which was originally his father's amp for a general service and cab refurb. I have have to say it was in lovely original condition, the trem didn't work, (no surprise there!) but was soon sorted after changing the oscillator caps and also needed new output valves, as they get a hard time in these cathode biased amps. Fitted a new brass vent and some minor re-gluing and cleaning of the tolex, and she looked and sounded stunning. Lovely job.    

Marshall 1987X 50watt head

Just doing a few light jobs at the moment, and this 1987X 50watt head was too nice to resist. It was blowing the HT fuse, which turned out to be a faulty output transformer (shorted primary turns), which had also cooked the output valves as a result. Great service from Marshall providing a Dagnall replacement, but I have changed quite a number of Dagnalls in recent times, just hoping their QA is up to scratch.       

Marshall JCM 2000 DSL 401 

This DSL 401 was blowing the mains fuse, so the owner asked me to investigate, interestingly it was fitted with Mullard EL84s, which the owner knew nothing about, and actually turned out to be marginal on output - lesson here, just because they are old Mullards, doesn't mean they are good! Unfortunately the mains TX had shorted primary turns and was overheating and melting the varnish impregnation. All sorted with help from Marshall.  

Fender SF VibroChamp - spring reverb mod

Well 2017 got off to a very bizarre start, I was rushed in to hospital for emergency bowel surgery and as a result am completely out of action. I have however, been doing a bit of light tinkering, and decided to add a spring reverb to my own SF VibroChamp and to be honest it has transformed the amp into (IMHO) the perfect Fender practice or small gig amp. When I am back on my feet proper, it is something I could offer commercially if there was any interest.    

20 x KT88 Disco power Amp

I sometimes get asked to work on some unusual valve projects and this one is no exception, A customer of mine runs a number of these amps in various configurations - he also has his 'babies, 10 and 12 x KT88s, all which run his bass, mids and top ends. They produce such an awesome sound - much better than anything solid state you will ever hear!    

Orange OR15

An old customer of mine Frank, asked me to look at his Orange OR15, a super little 2 x EL84 amp with classic Orange tones. The amp was suffering from very low and distorted output. A quick check on the bench revealed it was the PI (phase Invertor) valve that had failed. A quick way of identifying pre-amp or power amp problems is to use the send and return sockets to split the two, so connect the send output to the input of a known good amp. Similarly put an input signal into the return socket to test the power amp.     

Trace Elliot V4 Bass head

An old customer of mine Steve, asked me if I would look at his pride & joy, a Trace Elliot V4 220watt bass head, which he used to gig with regularly, back in the day! It had been in for a service at a Trace Elliot specialist several years ago and came back blowing fuses and generally being a lot worse than when it went in. Steve wanted it back in good order for his son, so the fault was quickly diagnosed to blown rectifiers on the screen grid HT supply caused by a shorted output valve and too big a HT fuse (KT88s don't take prisoners!) There are two separate HT supplies on the V4, as the anode is supplied at a much higher voltage than the screens. Anyway all now good and she sounds wonderful.   

Randall V2 100watt head

Wayne and I had been discussing whether or not he should take the plunge with this Randall V2 100watt head advertised on EBay, in the end he got the amp for a great price, but it had a problem with mains derived hum. I tracked it down to a faulty main power supply cap (very unusual to be honest), which was replaced and the amp was restored to its former glory. Looking forward to hearing Wayne giving it large with this beast of an amp..    

Fender Tonemaster & Supersonic 60

I was contacted by Richard, guitarist in the Houndogs a brilliant contemporary Rockabilly band , who uses his amps for gigging, but was having problems with them both, the Supersonic was losing volume after half an hour or so, and the Tonemaster, had an intermittent loss of volume coupled with increased distortion. Both turned out to be problems which I suspect were on the amps from new. The Tonemaster uses a star point earthing system (see the white wires joining at a common point in the photo). One of the earths to the pre amp stages  was poorly soldered and intermittently coming adrift. The Supersonic had a badly soldered pin on the pre-amp ribbon cable connection, which was opening when the amp got hot. But I am pleased to report all sorted, and Richard is once again a happy rocker!         

1958 Fender Tweed Champ 5F1

Many thanks to Steve for bringing me his wonderful 1958 Fender Tweed Champ 5F1, the amp needed quite a lot of work to restore it to its former glory, including a mains transformer rewind, full electrolytic cap replacement, new valves and volume pot. The amp sounded wonderful, and shortly after getting it back, Steve performed solo at a jazz concert for two hours using only the amp and his guitar, so clearly smiling faces all round! 

Fender Brownface Super Amp

I was contacted by John, who is the owner of this lovely early 60's Brownface Super Amp. It had been worked on in the past and John was not 100% happy it was producing the classic Brownface sound, so asked me if I could work through the schematic and get the amp back as original as possible. It was the 6G4-A model, the one with the fabulous harmonic tremolo. John is technically pretty amp savvy, and between his research and my implementation, we got the amp pretty much spot on, as well as getting the amp back as per the original schematic plus a replacement Triad 45216 output TX. we also added a couple of enhancements such as a bias trim pot and a 'bright' switch  utilising the redundant ground switch. All in all, now a very sweet sounding amp, with the best trem I have ever heard!           

Carr Mercury combo & Mojave Coyote head

I was asked by Julian a new customer, if I would look at his two awesome amps, The Carr was suffering from an annoying rattle and the Mojave, was just not sounding its best anymore. These are two seriously well built amps, though with completely differing chassis layouts. Both turned out to be straightforward fixes, the Carr had a microphonic valve in the high gain V1 position. The Mojave needed two new EL84 output valves as they are cathode biased and run very hot in the amp. Both had a full service, plus the Carr had a small mod to the attenuator circuit, all in all, lovely amps and a happy customer = result !    

Fender Champ 'Red Knob' - Torres mods

I was contacted by Mark, who had been given the Champ by his brother, its fair to say the amp was not performing at its best and in addition Mark wanted to unlock more of the potential from the amp. Having carried out research on improving Champs, Mark opted for a number of Torres modification kits (from the US), and asked me to fit them together with a valve test & general service. Well I'm pleased to report the project was a complete success, the mods together with a service and new TAD 6L6 GC transformed the amp, giving it much more character and opened up a many more options tonally, Mark is now one happy camper and is a pretty handy axeman to boot!!        

Marshall 1962 re-issue Tremolo 50 watt combo

Tony asked me to service his lovely re-issue Tremolo 50 watt combo, there were no dramas it just needed a set of output valves, a re-bias and general service. The combo is slightly unusual in that it uses 6L6 output valves rather than traditional EL34s, which gives it a slightly warmer feel, and is perfect for Tony's range of guitars and style of playing.    

Marshall 1959 Plexi re-issue 100watt head & 2150 combo

Many thanks to Gary for trusting me with his 1959 Plexi 100watt head and 2150 100watt combo (rare beast indeed!) Gary plays lead with The Lengthmen who play old school punk. Gary wanted the head converting to JCM800 + extra gain spec.to suit the style of music the guys play. He also is a bit of a collector, so watch this space for more of Gary's great gear!     

Fender Twin Reverb '65 re-issue

Many Thanks to Brian for entrusting me with his awesome Fender Twin Reverb '65 re-issue. The amp came in for a general service plus non working foot switch (which turned out to be the stereo jack plug connections). Fitted with Sovtek 5881's it has a slightly warmer tone than your typical TR and all the better for it in my opinion - glorious amp, but a heavy beast!   

Cornford Roadhouse 30

Another interesting amp in for service, a Cornford Roadhouse 30, thanks to Sam at Chesterfield Rehearsal Space, this is one of his customer's amps. What is interesting about this amp is that it runs 6L6GCs and is cathode biased, (and runs 'hotter' which makes it sound quite distinctive, with more break-up and overdrive than say a typical Fender 6L6GC based amp.     

Marshall JCM 2000 Dual Super Lead

I was asked by Alex Smart, lead guitarist of The Brookes if I would look at his JCM 2000 DSL as it had 'flashed' & blown the HT fuse after 10 hours continuous use in the studio. It turned out to be the EL34 output valves, which were original and had finally given up the ghost! I also gave it a full service and re-bias on the slightly 'hotter' side to match Alex's style of playing. Now fully refreshed and one powerhouse of an amp!  

Marshall JMP Master Model 100

Another classic Marshall from the Curly Lead Recording studio in Nottingham. It just needed a thorough service, including valve test & re-bias, I also changed the bias capacitors and the mains on/off switch, plus various other items. Normally I also hard wire the impedance selector switch, but in this case it had never been touched and was in good electrical condition. The sound is classic AC/DC or Slash Marshall heaven (if you are into that kind of thing!)   

1981 Marshall JMP Master Model 50

I was asked by Dave, owner of Abbey Road Music to have a look at his Master Model 50 (2204) combo, one of the many amps in his Curly Lead studio. It just needed a good service, re-bias and a general clean up of the cab & tolex. I also did a couple of small mods to the pre-amp to thicken up the sound at lower volumes, all in all a really classy combo.   

Audio Innovations Series 500

I had the pleasure of servicing this beautiful 25watts per channel, class A amp recently, Michael the proud owner had thought he could smell burning one day whilst switching on, so wisely decided to have it checked over. The fault was pretty evident - two of the HT power supply caps had failed, so were replaced together with a full service, valve and bias check. The amp sounds wonderful even through my cheap test speakers and IPad !  

Elpico AC52 'Combo'

I was asked to look at this service job by the guys at Guitar Spot in Beeston, it had very low and distorted output. Well I got there in the end but not before changing a preamp valve, screen grid resistor, nearly all the signal caps, repairing the PCB and changing lots of brittle wiring.
Although it looks like it has had a hard life, it now sounds so much better and quite loud (class A single ended EL84). Its bigger brother the AC55 is quite famous - answers on a postcard as to why :-) 

1974 Marshall Lead & Bass 50

The guys at Guitar Spot in Beeston asked me to look at this lovely Lead & Bass 50, quite a rare model in combo format, complete with cobwebs! it didn't need much work to return it to its former glory, valves, pots & input jacks plus a re-bias. Classic Marshall tones! 

1972 Fender Twin Reverb Silverface

I was asked to look at this refurbishment project by the guys at Guitar Spot in Beeston, it had been stood in a garage for many years and was looking a bit sorry for itself! The basic amp was in very original condition, so just needed a full cap job, new valves, a few signal cap changes, new grille cloth, replacenment reverb tank, replacement speakers and a good general tidy-up. Really enjoyed this one, she sounds and looks amazing, and is turning out over 100 watts on the soak test. Many thanks to Guitar Spot for trusting me with their customer's pride and joy! 

Fender SF Vibrochamp

lovely little amp that came over from the US, so needed converting to UK spec. this involved fitting a new mains transformer (from TAD, Germany, direct Fender replacement), new mains cable / plug, full service and safety inspection. It is also good practice when changing a mains transformer to double check the HT voltage and the bias current (even though it is a class A, cathode biased amp).

Marshall JTM60

A good friend of mine asked if I could have a look at his JTM 60 which was losing output and emitting loud cracking noises from time to time - all classic trademarks of an output transformer with either shorted turns or internal arcing. The JTMs are particularly prone to it and I do replace them with higher wattage units as you can see in the photos.  

Fender SF Musicmaster bass

This is an early SF Musicmaster bass, which used  6AQ5A  output valves rather than 6V6GTAs, they are also unusual in that they have a  transformer coupled phase splitter. This one was noisy, and needed a full overhaul including valves and power supply caps.  

1979 Fender SF Princeton Reverb

This was my own amp (a '79 silverface), detailing various jobs I have done on the amp over the years. This includes mains transformer change (imported from the US), cap changes, re-biasing, new baffle to accommodate a 12 inch Jenson, reverb leads, generally everything to keep it in tip top shape.

1971 Vox AC 30 - Stolec model

This is probably the biggest project I have undertaken to date. Without doubt the 'Stolec' era AC30s were the worst amps of this iconic brand. They would literally catch fire, as this one very nearly did at some point in its life. Some models were fitted with a reverb which never worked from new. The main culprit being cost cutting measures and adoption of '70s TV type PCB technology (if you have ever repaired a '70s TV you will know what I mean). I had to first of all draw a schematic, as non actually exist of this particular reverb model, then design and build new PCBs for the output stage and reverb, plus a full cabinet refurb and face plate as the photos show.   

Fender Deluxe 85 'Red Knob'

Just to demonstrate I do repair solid state amps from time to time, here we have a Fender Deluxe 85 Red Knob combo made in approx. 1987. This one was completely dead except for the ominous mains hum from the speaker. The output transistors had blown (TIP 142/147 power Darlingtons) and the emitter coupling resistors were open circuit. All relatively easy to fix.  

Peavey Classic 20

Interesting 2 x EL84 amp, with unique wrap around circuit board, making them a little bit awkward to work on but a really compact design. This one needed the output valves replacing and the cathode bias resistors (1W) had been overheating, so were changed as a precaution to 3w wirewound types. 

Ashton Viper 50

A very underrated amp, designed in Australia, built in PRC, it has many nice features, such as the fitting of 1 ohm cathode bias resistors taken to external terminals making biasing a doddle. With 2 x EL34 output valves, it is very loud to boot and has tonnes of gain. This one just needed a service and I made an aluminium grille for the rear to replace a missing one.      

Homebrew reverb unit

One of my own 'hobby' projects, based on the classic Fender 6G15 design, I did cheat on this and have the cab and faceplate made! 

Pignose 40V

Don't see too many of these amps, they are very compact and difficult to work on, this one had very weak output and uneven loads on the output valves (one was badly red-plating). Guess what -  another output transformer bites the dust plus new output valves and re-bias.

Laney LC15R

One of many Laney LC series amps I have worked on over the years, and as I find time and time again, the problem lies with marginally rated output transformers, this amp was no exception!  

1966 Fender Bandmaster BF

Really enjoyed this refurb, it came in a sorry state, DOA, with a poorly replaced O/P TX, missing valves, leaky caps etc. It needed a new O/P TX, choke, replacement caps, but as you can see from the photos, it left us in tip-top shape!   

Sound City 50 Plus

A real tidy amp this one, but suffering from more background hum than usual (and they are a noisy amp anyway!) Full recap job, re-bias, pots cleaned and a number of the carbon composite resistors changed. The valves were tested and serviceable, but did recommend they were also replaced. The amp was so much better when finished. 

Ashdown Peacemaker 40 & 20

I love this range of British made amps, despite the fact they are an absolute nightmare to work on!! To get access to the chassis you have to remove the reverb tray, the speaker & baffle and the bottom wooden strips that hold the back panel on! Getting to the PCB (solder side) is yet another mammoth task involving splitting the front and back of the chassis. No wonder the majority of repairs get done on the component side of the PCB (often badly - see photos). 

Orange AD15 (R)

Another project where I added a valve reverb circuit to an existing amp, this time an Orange AD 15. Again it was designed to be easily removed and did not alter the face plate. No images of the actual circuit on this one I'm afraid. 

Fender Champ - Red Knob

Great little amp, properly sized transformers, generally well put together IMHO. If I had one grumble it would be the quality of the reverb tank - not something you expect to see on a Fender.
This one just in for a service and check over, valves, pots, rattles and squeaks - the usual - but given a clean bill of health.

Peavey Encore 65 - various

I have seen a number of these over the years and to be honest the photos blur into one, so I thought I would show a bit of a montage of views. Being US made these amps are pretty robust, in fact the transformers are rock solid. In all cases it has been resistor / PCB faults mainly due to age. Please note - the capacitor 'pack' on the last image is not my handy work!

Vox AC30 CC2

In my opinion, from a chassis and cab perspective, as close a match to the original AC30 as you will find. With some interesting features such as switchable cathode bias resistance and HT smoothing cap values (vintage/modern!) They are however heavy on rectifier valves, which I believe is not helped by the standby switching arrangement (lifting the TX centre tap from ground). This one was blowing HT fuses and was a combination of output valves and rectifier valve. 

Fender SF Twin Reverb

Another monster classic Fender, the twin reverb, this one just needed a cap job, valve / bias set-up and general service and soak test.

Fender Red Knob 'The Twin' 

This brute of an amp was DOA when it arrived for repair, fortunately it was a pretty quick fix, as you can see the main HT volts dropper resistors were open circuit and were replaced by higher wattage types. I also changed a couple of the front jack sockets as they are prone to breakage on all of the Red Knob '80s amps. I have to say this is probably the loudest amp I have ever tested! Now owned by my good friend Stan, who uses it to good effect with his killer guitar playing.  

1965 Fender BF Super Reverb

The holy grail of Fender tone................... 
The amp came to me in very poor condition, it had certainly had a hard life! It required complete refurbishment including importing a new cab from JD Newell in the US, 4 new Jenson P10R speakers, reverb tank and of course a full overhaul, re-cap, re-valve and test.  

Crate Vintage Club 30 - Blonde

This amp was actually a water damaged insurance write off, I have repaired a few Vintage Club series amps and they are great to work on and built like tanks. This turned out to be very straightforward, thorough dry out of everything (the water never got near the chassis), replacement speaker and reverb tray (just in case), full service, new valves and away she went.   

Orange AD30R 

This classic British amp, came in with a non-functioning reverb, which actually turned out to be the Accutronics tank 'send' transducer open circuit, so had to be replaced. A little tip, never buy a second hand reverb tank (typically found on auction sites) - they never work, and are not worth even trying to repair!

Ashdown Fallen Angel 60 head

This Fallen Angel 60 came in with very low distorted output, following a visual check and a full test on all the valves, we had to dig a bit deeper using the signal generator, scope and dummy load. Everything was pointing to the output TX as it was showing out of balance on the primary windings. Just to be 100% sure I always substitute the transformer with one from my test rig and sure enough the original did have shorted turns and had to be replaced. You can see the size of the replacement 60watt TX compared to the original Chinese unit!

Fender Blues Junior

This was a MIM cream PCB version, they also come in green! - there is a lot of discussion about the differences on the web, so I won't go into it here. This one was a DOA, to cut a long story short the problems were faulty O/P TX and reverb tank. Not my favourite Fender amp, the EL84 valve bases can overheat and crack the tracks on the valve base PCBs, though not in this case.  

Roland Jazz Chorus 120H

A solid state icon of an amp, built like a tank! and has an excellent reputation amongst musicians. This one just needed a service and a reverb tank connection repair and she was good to go for another 30+ years.    

Fender Bassman 70 SF

Interesting project this one, I was asked if I could add a valve reverb to the normal channel of the amp, but it had to be non-invasive and easily taken back to original, so I came up with this design, which fitted on top of the cap cover, and utilised the existing HT and heater supplies, my own pcb design and an Acutronics reverb tank and rear mounted revreb pot. In addition I converted an old Peavey 112 amp to solid back and made a matching cab. All worked a treat!   

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